According to the 2003 addition of the International Building Code, structural engineers were permitted to design chevron braced steel frames to unlimited heights in Seismic Design Categories A, B, and C assuming R=3 without following seismic detailing provisions. A significant portion of the United States falls within these categories and may be vulnerable to nonconservative seismic designs. To date limited research has been focused on the seismic performance of structures in these low to moderate seismic regions.it was under construction at the time of the earthquake and the full working dead
load was not acting on the system. ... Bleacher Roof Structure The roof structure
for the bleachers of the football field, California State University, was built around
anbsp;...